Electric-arc lamp



(No Model.) 2 Sheets-Sheet 1.

F. A. GILBERT 8v E. O.LU1\IDIN.- ELECTRIC ARG LAMP.

No. 603,630. Patented May 10,1898.

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A 2 Sheets-Sheet 2. P. A. GILBERT 8v E. 0. LUNDIN.

ELECTRIC ARC LAMP.

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UNITED STATES PATENT OFFICE.

FREDERICK A. GILBERT, OF BROOKLINE, AND EMIL O. LUNDIN, OF BEACHMONT, MASSACHUSETTS.

ELECTRIC-ARC LAM P.

SPECIFICATION forming part of Letters Patent No. 603,630, dated May 10, 1898.

Application filed July l, 1897. Serial No. 643,183. (No model.)

To all whom t may concern:

Be it known that we, FREDERICK A. GIL- BERT, of Brookline, county of Norfolk, and EMIL O. LUNDIN, of Beaehrnont, county of Suffolktate of l\Iassachusetts,have invented an Improvement in Inclosed Arc-Lamps, of which the following description, in connection with the accompanying drawings, is a specification, like letters and figures on the drawings representing like parts.

This invention has for its obj ect the production of an inclosed arc-lam p of improved construction whereby among other features the trimming is greatly facilitated, means being provided for holding the upper carbon in place while removing the inner globe, so that the operator has both hands free.

The feed-controlling clutch and the con tact for the upper carbon are of novel and highly effective construction, and the cap or cover for the inner globe is provided with a novel valve, through which the upper carbon can pass without binding when in use.

The armature of the solenoid is mounted on a tubular member surrounding the upper carbon, the upper end of said member having a piston to enter a centrally-supported dash-pot at the top of the lamp, thereby greatly simplifying the construction of the parts, the feed-controlling clutch being mounted on the lower end of the tubular member.

We have provided novel and effective means for automatically cutting the resistance-coil out of circuit when the lamp is started, the coil being in circuit only when the lamp is not burning or when the upper carbon is burned out, and the resistance-coil is so located as to greatly economize space.

It has been found in practice that in the ordinary inclosed series arc-lamp if the carbon burns out the voltage of the arc will run up to ninety or one hundred, burning out the globe and lower-carbon holder; but in our improved lamp the voltage of the are will not be increased under such circumstances, so that danger of burning out the globe or lower-carloon holder is decreased to a minimum.

By the construction hereinafter described the upper carbon will when burned out be released from the controlling-clutch, so that the ends of the carbons will come together, and

the current will then pass therethrough and through the series coil to Ithe line without damage to the parts of the lamp. Should the u pper carbon by any chance stick when the lamp is burning, the safety cut-out will be operated automatically to cut the lamp out of circuit.

The general construction of the lamp and the Various novel features embodying our invention will be hereinafter fully described in the specification and particularly pointed out in the claims.

Figure l represents in elevation an arclamp embodying our invention, the outer globe and the lamp-case being shown in section, the lamp being shown as in use or when burning. Fig. 2 is a partial vertical sectional view of the armature and coils with the controlling-clutch for the upper carbon in elevation, the clutch being in unclutched position. Fig. 3 is an enlarged longitudinal sectional view of the contact member for the upper carbon. Fig. 4t is a transverse sectional view thereof on the line x o5, Fig. 3. Fig. 5 is an enlarged top or plan view of the valve or closure for the inner globe. Fig. 6 is a diametral sectional view thereof on the line x oo', Fig. 5. Fig. 7 is a detail in elevation and on an enlarged scale of the removable globe-holder and support for the lower carbon. Fig. 8 is a transverse sectional view thereof on the line y y, Fig. 7. Fig. 9 is a partially diagrammatic view of the coils and circuits. Fig. l() is a lower end view of the armature and tube in which the upper carbon travels. Fig. l1 is an enlarged view, in front elevation, of the lower part of the lamp with the spider drawn down. Fig. l2 is a top or plan view of the cross-bar shown in Fig. 1l with its depending hub, and Fig. 13 is a perspective view of the seat for the inner-globe holder.

Referring to Figs. l and 2, the lamp-frame comprises an open up perbody portion A, preferably made as a metal casting having a cylindrical base A', the sides having openings therein for the free circulation of air to aid in maintaining the adjacent portions of the lamp cool.

The base A has (see Fig. 2) an upturned hub AX and a central aperture through which is passed a lon gitudinally-movable metal tube B for a purpose to be described, the cage-like IOO body A receiving therein the usual serieswound and shunt coils C and C, respectively, the core upon which the coils are wound resting on the base A and being positioned by the hub AX.

A top A2, having an inner hub A3, (see Fig. 2,) closes the body portion, said hub being shouldered at 2 to support a spring S, which assists the solenoid in lifting the tubular clutclractuator B, the lower end of the hub being recessed to permit full movement of the armature CX.

A washer 3 of insulating material is interposed between the base A and a ring A4, held in place by suitable insulated screws 4, said rin ghavin g attached thereto depending members A5, preferably tubular, into which fit telescopically rods A6, (see Fig. 1,) secured to a spider A7.

The lower ends of the tubes A5 are rigidly attached to a cross-bar a, having a central opening a', Fig. l2, and cut away at CL2 between the two lateral ears a3 at the front of the bar, two similar ears a3 being extended laterally from the back of the cross-bar, and beneath the latter depends a tubular hub a5, concentric with the opening` a', said hub being adapted to pass through the threaded part A of the spider. The spider is held in place by a suitable nut A8, Fig. l, locked onto the projecting lower end of the hub a5 in usual manner, and the shade or outer globe GX is supported normally in the position shown in Fig. l by a socket A9, held in place by the threaded part A70 of the spider.

The seat a4 for the inner-globe holder is shown separately in Fig. 13, it being substan tially an open ring-like member having ears am, which are so disposed as to register with the ears a3 of the cross-bar, the seat being held in place on the cross-bar by insulated screws 5 6, while washers 7 of insulating material are interposed between the cross-bar and the seat a4.

The seat a4 is provided with diametricallylocated clamping-screws 8, which are engaged by oppositely-turned hooks d, (see Figs. 7 and 8,) laterally7 exten ded t' rom a casting D, adapted to rest on the seat d4, said casting having a central tubular portion CZ', through which is extended the lower carbon L, a socket (Z2 receiving the lower end of the inner globe G. A clamping-screw d3, extended through the tubular portion d of the globe-support, holds the lower carbon iirmly in position.

It will be seen by viewing Fig. S that when the screws S are loosened a partial turn of the globe-support D will withdraw the hooks CZ from engagement with the said retainingscrews, so that the globe-support and globe can be removed bodily from the lamp. )Vhen replacing the globe-support, the reverse operation is carried out, and when the hooked ears d are in position the retaining-screws 8 are tightened. This serves to center the lower carbon as well as to provide a readily-operable detachable connection for the globe-support.

Referring to Fig. 2, the clutch-actuator is shown as a tube B, extended longitudinally through the open body A of the lamp, said ytube contacting with the base A', although passing freely therethrough, the armature CX being rigidly secured to the tube by a clampscrew 0X. (See Fig. l0.) The armature is sleeve-like in form, having a conical upper end and shouldered at c', the armature being longitudinally split, as shown in Fig. l0, so that it may be tightly compressed upon the clutclractuator B by tightening the screw 0X. The shoulder c serves to limit the downward movement of the armature by coming in contact with the upturned hub A of the base.

The operation of the armature and its series-wound coil C is as usual in other lamps, the current acting through the solenoid to raise the armature and with it the clutch-actuator, the shunt-coil depressing the latter.

The lower end of the tube B is extended below the base A' into a longitudinally-slotted depending guide f, secured to the under side of the base A and having attached to its lower end a tube f in alinement with the clutch-actuator B. This tube has rigidlysecured thereto a contact device for the upper carbon, said device comprising a disk g, (see Fig. 3,) having an annular flange g on its under face, the disk supporting a cylindrical casinggz, having screwed into it a base g3, suitable screws lO holding the casing and disk g together. As clearly shown in Fig. 3, the base is curved upward from its periphery to a central boss g4, surrounding an aperture g5, through which the upper carbon L freely passes, the top of the base thus presenting an annular seat fora series of radially-disposed independently-movable members gx. Each of said members has a straight outer edge, an upturned lug g at its upper end, and a convexed inner edge, increased in width at g7, the lower corner of each contact member resting on the annular seat formed by the base adjacent the casing g2. The shape of the contact members is such that they tend to drop inward by gravity toward the longitudinal axis of their supporting member, the flange g serving to limit such inward movement when the upper carbon is withdrawn by enn gaging the lugs g, lVhen the carbon is inserted, the contact members g are pushed outward sufiiciently to permitits passage between them, the center of gravity of each mcmber causingit to rest lightly yet su rely against the carbon to form a goed contact therewith, said contact members and their support being of course made of metal. These gravity contact members always insure a constant Contact between the upper carbon and the circuit, the current passing to the support and contact members, as will be described, and by their use any sparking or arcing is prevented when the clutch-wheels leave the carbon.

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A ring h, secured to the casing g2, has extended laterally therefrom a slotted ear h, through which is extended loosely an arm h2, pivotally connected at its lower end with the inner-globe cover or cap hX, said arm being notched at its inner side at 12 and having a finger h3, by which it and the cap hX may be lifted. Vhen the cap is in place on the globe G, (see full lines, Fig. 1,) the upper notch engages a cross-pin 13 in the ear 1f, a pin 11 preventing accidental withdrawal of the arm from the ear.

The downwardly-flanged cap hX fits over the upper edge of the globe G, while the central portion of the cap is depressed at h4, Fig. 6, and provided with an upturned hub h5, ext-eriorly threaded at its upper end at h6.

A centrally-apertured disk 117 has on its under side a flange threaded at hs and outwardly bent at b9 between the disk and the threaded portion, so that when the latter is screwed on past the thread hof the hub the disk will be held onto the cap, while free to move laterally a limited amount. The upper carbon passes freely though closely through the disk 717, which acts as a valve to close the upper end of the globe, but should the carbon be slightly out of alinement or the globe slanted the lateral play of the valve prevents the carbon from binding. Now when the trimmer wishes to trim the lamp he lifts the arm h2 by means of the finger h3 until the lower notch l2 engages the detent-pin 13, holding the arm in dotted-line position, Fig. 1, and at the same time the cap 71X is inclined and raised, the inclination of the cap from the horizontal causing the upper carbon to be caught and lifted with the cap. The upper carbon will be held up thereby as long as the arm h2 is retained lifted by the detent, so that the trimmer has both hands free to effect the proper trimming of the lamp. Vhen the trimming is finished,

a slight lift on the finger h3 will release the arm, so that it and the cap will return to normal operative position, at the same time releasing the upper carbon.

In trimming, the globe G is removed while the cap is lifted, after which the cap is lowered as far as it will go and the upper carbon is pushed up through it and then pulled out, so that a new one can be inserted. The cap is then lifted, as before, holding the upper carbon stationary while the globe is replaced.V

A long carbon can be readily inserted by putting the lower end down through the slotted hub a5, then turning it up vertically to be passed up through the contact and feed-controlling devices, the opening a2 in the crossbar and the open seat a4 permitting the turning up of the carbon.

rlhe feed-controlling clutch for the upper carbon comprises two preferably grooved metal wheels 1), loosely journaled in elongated substantially horizontal slots 1 formed in bifurcated carriers h2, pivoted below the wheeljournals at b3 to arms on a ring 114, sliding on the tube f', which is longitudinally slotted at f2 to permit the peripheries of the oppositelymounted wheels to engage the carbon within the tube. rlhe carriers are outwardly bent to form arms which are pivotally connected by links 195 with lateral projections on a ring 126, rigidly secured to the lower end of the tubular actuator B, and brake-shoes 111, adapted to bear at times on the peripheries of the wheels, are pivotally mounted in outward extensions 19s of the carriers. The lateral proj ections of the ring h6 extend through the longitudinal slots of the guide f, as shown in Figs. 1 and 2, permitting movement of the ring up and down as the actuator B rises and falls with the armature CX of the series wound coil C. Now, owing to the relative position of the wheels, brake-shoes, and fulcra b3 of the carriers, when the actuator is raised the links brock the carriers and bring the brakeshoes 127 to bear against the wheels, forcing them against the carbon and stopping their rotation, so that the carbon is lifted. lVhen the amount of current passing through the shunt-coil C/ increases, the armature and clutch-actuator B will descend, and the carbon is lowered, still held by the clutch, until the ring 1)'1 is stopped by an adjustable collar 1910 on the tube f', and further descent of the ring h6 will throw off the brake-shoes, releasing the carbon. By adjusting the collar 1110 the separation of the carbons is mechanically effected to vary the length of the arc.

The current enters the lamp by the line wire 1, Figs. 1 and 9, which is electrically connected with the metallic body A, the current passing thence to the tube B and to the carbon by several paths, principally, however, by the contact members gx, the contact device as a whole being diagrammaticall y represented in Fig. 9 at C5.

Ve have herein shown the lamp as adapted for use with constant direct currents, the windings of the coils being arranged for that purpose; but by altering the windings and necessary connections the lamp may be used for other systems.

The current passes from one carbon to the other, forming the arc when the lamp is burning, and from the lower carbon L by insulated wire 1 to one end of the coil C, through the latter, and back to line at 1. One end of the shunt-coil C' is connected electrically at c4 with the body A and its other end with the line-wire t' at c5, Fig. 9, so that if the arc becomes too long more current will pass through. the shunt, weakening the effect of the series coil C on the armature, which with the clutchactuator B will descend, so that the controlling-clutch will permit the proper feed of the upper carbon to properly shorten the arc and thereby maintain the proper length thereof.

The actuator B carries acontact c6, adapted at times to engage aiixed contact c7, mounted on and insulated from the body A, said fixed contact being connected by a wire 13 with a resistance-coil R', the latter being in circuit with line-wire 1 by wire1'1, Fig. 9. lVhen the IOO IIO

current is turned off, the cut-out circuit Z3 Z4 is closed and the carbons are in contact; but when the current is turned on to start the lamp the cut-out resistance R/ will cause enough current to pass through the series coil C to raise the armature and separate the earbons, such movement of the armature then breaking the cut-out circuit at cG c7, throwing out the resistance RC Sometimes the upper carbon might stick long enough for the cut-out circuit to be closed, cutting out the lamp, and then the carbon might be released, and as soon as the carbons come in contact the circuit will be completed through them and the cut-out circuit opened.

It will be seen that we dispense altogether with a holder proper for the upper carbon, it being controlled entirely as to its feed by the clutch device described.

The resistance-coil R is wound upon the exterior of the body B, insulated therefrom by a sheet m of mica, preferably, the windings being separated by air-spaces, as shown, and another resistance-coil R is similarly mounted on the body A above the cut-out resistance R. The resistance R is connected at its upper end at Z8 with the wire Z and at its lower end to the wire Z, so that the more resistance is inserted the greater will be the current in the series coil C and the greater the separation of the carbons and length of the are. By decreasing the resistance the current in the series coil will be reduced and the arc shortened, so that by varying the resistance the length of arc is regulated.

The resistance is varied by a sliding contact cl2, mounted on a guide cl3, insulated from the body A and connected at c1-1 with wire ZX, a set-screw 015, Fig. l, holding the sliding contact in adjusted position, the contact moving over and contacting with the windings of the resistance-coil R.

Should the upper carbon burn out sufficiently to fall out of the controlling-clutch, the end of the carbon will come together, the current then passing directly through the carbon and series coil to line without any tendency to burn out adjacent par-ts.

The cut-out circuit operates automatic-ally to cut the lamp out of circuit if the upper carbon should stick, for the tube B will gradu ally descend until the terminals cG c7 of the cut-out circuit contact, thus throwing the lamp out of the line-circuit.

Upon suitable standards 35 (see Fig. 2) on the lamp-body A is supported a cylinder D3, closed at its upper end and receiving therein a piston D4, fast on the upper end of the actuator B, said cylinder and piston forming a centrally-located direct-acting dash-pot to regulate the movement of the upper carbon and prevent sudden jumps thereof which might be caused by the operation of the feedcontrolling mechanism.

The upper part of the lamp is inclosed in a light ornamental sheet-metal protective casing M, open at top and bottom to permit free circulation of air therethrough to aid in keeping the lamp cool. At its lower end the casing is flared at M to extend over the top of the outer globe GX and is provided with airinlet perforations mx, outlets m3 being provided at the upper end of the casin A cover M2 incloses the top of the body A and the adjacent parts, protecting them from dust and injury.

The lamp-hanger II may be of usual construction, with leaders II/ for the line-wiresZ and Z.

Our invention is not restricted to the precise construction and arrangement as herein shown, as the same may be varied without departing from the spirit and scope of our invention.

Having described our invention, what we claim as new, and desire to secure by Letters Patent, is-

l. In an arc-lamp, ay feed-controlling clutch including rotatable members to directly engage the carbon, rocking carriers for said members, brakes mounted on the carriers to prevent rotation of and press said members against the carbon, and an actuator to operate the carriers and control the brakes to thereby raise and lower the clutch bodily,sub stantially as described.

2. In an arc-lamp, a feed-controlling clutch including rotatable members adapted to directly engage the carbon, rocking carriers for said members, brakes mounted on the carriers, and an actuator to throw the operation of the brakes and thereby throw the clutch into and out of operation and also to raise and lower the same bodily, combined with an adjustable stop to effect release of the carbon at a predetermined point, substantially as described.

3. In an arc-lamp, a feed-controlling clutch IOD comprising rotatable contact members, rocking carriers therefor, brakes mounted on said carriers, to press the contact members against the carbon and prevent their rotation, a tubular actuator in which the upper carbon is freely movable, and connections between said actuator and carriers,to operate the latter and thereby regulate the feed of the carbon, substantially as described.

4. In an arc-lamp, the la1np-body, a depending guide having alongitudinally-slotted, tubular extension through which the upper carbon is loosely extended, combined with a controlling-clutch for said Carbon, comprising rotatable contact members, rocking carriers therefor, a support for said carriers, adapted to slide on the tubular extension, brakes 011 the carriers to act upon and press the contact members against the carbon, a clutch-actuator, and connections between it and the carriers, to operate, substantially as described.

5. In an arc-lamp, a globe having a removable cover, through which the carbon passes, and means to lift the cover and retain it lifted .TIO

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from the globe for trimming, the cover when lifted engaging and holding the upper carbon stationary, substantially as described.

6. In an arc-lamp, a globe havinga removable cover through which the carbon is normally adapted to freely pass, a lifting-arm to which said cover is pivotally jointed, and a detent to retain said arm and cover lifted, the cover when lifted inclining to the horizontal and engaging the upper carbon to prevent its downward movement, substantially as described.

7. In an arc-lamp, a globe-cover having a central upturned hub exteriorly threaded at its upper end, a disk having an opening in which the carbon snugly lits, and a downturned, outwardly-bent flange on said disk, threaded to engage the hub of the cover, the bent portion of the flange permitting lateral movement of the disk after separation of the said threaded portions, substantially as described.

8. In an arc-lamp, a globe-cover having a central upturned hub, a coperating disk having an opening in which the carbon snugly fits, and means to retain the disk on the cover while permitting free lateral movement about the hub, substantially as described.

9. In an arc-lamp, a globe-cover having a central opening through which the carbon loosely passes, a cooperating disk apertured to snugly receive the carbon, and a detachable connection between the cover and disk, permitting relative lateral movement thereof without separation, substantially as described.

10. In an arc-lamp, a controlling-clutch for and to directly engage the carbon, a longitudinally-movable tubular actuator therefor in which the carbon is freely movable, a cut-out circuit in which said actuator is included, and a circuit-controller one member of which is fixed and the other mounted on the actuator, movement of the actuator to separate the carbous in starting the lamp breaking the cutout circuit, substantially as described.

11. In an arc-lamp, an open cylindrical body, series-wound and shunt coils inclosed therein, and a resistance-coil wound upon the exterior of said body and insulated therefrom, whereby said resistance-coil is supported independently of the series and shunt coils, substantially as described.

12. In an arc-lamp, a cylindrical body, series-wound and shunt coils inclosed therein, a resistance-coil Wound upon the exterior of said body and in shunt with the series coil, and a sliding regulator to adjust the resistance, substantially as described.

13. A contact device for electric-lamp carbons, comprising a supporting member, and a plurality of independent gravity contact members mounted to rock about their lower ends, said lower ends resting on the bottom of the supporting member, the upper portions of said members having enlargements on their inner faces adapted to rest against the surface of the carbon, substantially as described.

14. A contact device for electric-lamp carbons, comprising a tubular support having a centrally-apertured base, a plurality of independently-movable gravity contact members, mounted at their lower ends on said base and radially disposed around the aperture therein, adapted to rock on their lower ends and move their upper portions into contact with the carbon, and a stop to engage the upper ends of said contact members and limit their inward movement, substantially as described.

15. A contact device for electric-lamp carbons, comprising a tubular support having a centrally-apertured base, and a series of radiallydisposed gravity contact members mounted on said base and normally moved by gravity toward the longitudinal axis of the support, the lower ends of said members rest-ing on the base adjacent the tubular support, substantially as described.

16. In an arc-lamp, a main body portion, depending arms connected at their lower ends, clamp-screws on said connection, and alowercarbon holder provided with oppositelyturned, hooked ears to engage and be held in place by said clamp-screws, substantially as described.

17. In an arc-lamp, a detachable lower-carbon holder having a globe-socket and oppositely-turned hooked ears, combined with a support having clamp-screws to be engaged by said ears, to retain the holder in place, substantially as described.

18. In an arc-lamp, the main body portion, depending arms connected at their lower ends by a cross-bar, a hub thereon longitudinally slotted at one side, and a lower-carbon holder detachably mounted on the cross-bar, substantially as described.

In testimony whereof we have signed our names to this specification in the presence of two subscribing witnesses.

FREDERICK A. GILBERT. EMIL O. LUNDIN.

Witnesses J oHN C. EDWARDS, LAURA T. MANIX.

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